The purpose of this research is to create and evaluate an effective, exciting, and disseminable computer- based prevention program, Click City(c): Alcohol, for use by 7th and 8th grade students. The ultimate goal of Click City(c): Alcohol is to prevent the onset of heavy drinking during high school and post-high school. This proposed program is unique both in its delivery system and the development process. The program will be delivered over a school-based intranet (i.e., networked computers linked to a school-based server), which enables users to interact individually with the program and to share their experiences by receiving immediate feedback on their classmates' responses. Individual components of the program will be iteratively developed and empirically evaluated to assure that they are effective at changing theoretically based etiological mechanisms. Component development consists of focus groups, followed by user groups, and culminates in an empirical evaluation. We plan to develop and test approximately 24 components over the first two years of the study (Aim 1). The final Click City(c): Alcohol program will consist of 12 effective components delivered in six sessions over a three-week period in 7th grade. This is followed by two booster sessions, consisting of a total of 5 components delivered over a one-week period in 8th grade. (Aim 2). Educational newsletters to parents and teacher guides will accompany the program. Following development, we will conduct a group randomized trial to evaluate the efficacy of this program as compared to schools' usual alcohol prevention curriculum (Aim 3). We plan to recruit, stratify and randomly assign 26 middle schools to one of the two conditions, Click City(c): Alcohol and Usual Curriculum (UC). Students in the Click City(c): Alcohol and yoked UC schools will be assessed prior to the beginning of the 7th grade program, following the 7th grade program, following the 8th grade booster, which would occur approximately one year after the 7th grade program, and a follow-up assessment in the 9th grade to assess long-term outcomes, one year after the 8th grade assessment. The primary outcome will be heavy drinking in the 9th grade. Secondary short term (post, 8th grade) and long term (9th grade) outcomes will be extent of alcohol use and willingness and intention to engage in heavy drinking in the future.